<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>狂神说</title>
    <!--1.导入vue.js-->
    <script src="https://cdn.jsdelivr.net/npm/vue@2.5.21/dist/vue.min.js"></script>

</head>
<body>

<div id="app">
    <h1 v-if="ok">yes</h1>
    <h1 v-else>no</h1>
</div>

<script>
    let app = new Vue({
        el: '#app',
        data:{
            ok: true
        }
    });
</script>

</body>
</html>